HPAI Respiratory Protection

N95 is the minimum level respiratory protection approved by CDC/NIOSH for use for by individuals working with HPAI-infected birds.
HPAI Respiratory Protection - Articles


People involved in depopulation also wear surgical gloving, Tyvek suites, and goggles to prevent conjunctival exposure.

There are two sites that will provide you with some guidance:

The University of Nebraska Medical Center has an excellent synopsis in their report, Avian Influenza - Personal Protective Equipment Guidelines (PDF).